Guy Rump
Very unusual and impressive 🙂

Treehugger
Such models is certainly something to look at. 😄

Dave Burgess
The X-3 looked a lot more impressive than it performed. It was designed to test the Mach 2 envelope, but due to under-powered engines, it could only reach Mach 1 in a shallow dive. Still, it produced a lot of valuable data on the phenomenon of inertial coupling, which helped the development of aircraft such as the F-101 and F-104. They discovered that inertial coupling could be avoided by moving the rear horizontal surfaces out of the slipstream of the main wing, hence the T-tail on the F-101 and F-104.